Garlic, from medicinal herb to possible plant bioprotectant: A review

•Garlic-based compounds have strong antibacterial, antifungal and, allelopathic characteristics.•Garlic extract has shown to improve the crop quality and soil conditions under biotic and abiotic stress conditions.•Vegetable seeds primed with garlic extract revealed noticeable differences in germination indices and seedling growth (particularly root growth and fresh weights) in a dose-dependent manner.•Garlic allelochemicals also act as a plant biostimulant to enhance auxin biosynthesis and its transportation, resulting in a promoted root growth.